The invention concerns a drive device for a movable furniture part, comprising a force-actuated ejection element for ejecting the movable furniture part from a closed position into an open position and a locking device for locking the ejection element in a locking position, wherein the locking device comprises a control element, which is connected to the ejection element, and a sliding guide path for the control element. Moreover, the invention concerns an article of furniture with a furniture carcass, a movable furniture part movably mounted to the furniture carcass and such a drive device.
Since many years miscellaneous drive devices are produced in the industry of furniture fittings. Opening and/or closing movements of the movable furniture part (drawer, flap, door) are assisted or automatically affected respectively with these drive devices. Particularly known are so-called Touch Latch mechanisms, where an unlocking occurs by pressing onto the movable furniture part, whereupon the drive or ejection device opens the movable furniture part.
Lockable control elements guided in a sliding guide path are particularly suitable for such mechanisms. Mostly, these sliding guide paths are of a heart curve-shape or do have a heart curve-shaped section in which the control element is held or locked in a locking position of the locking device. By over-pressing the movable furniture part in an over-pressing position located behind the closed position, the control element is disengaged from this locking position (latching recess), whereupon the force-actuated ejection element can move freely and ejects the movable furniture part into the opening direction.
Besides the purely mechanical or functional requirements for such drive devices, the requirements regarding the operator convenience and the ease of use are increasing in recent times. There, an import aspect is also the noise development which is pretty high in numerous currently known drive devices. Among other things this is ascribed to the fairly high acting forces and also to the play between the moving components. The source for the noise development among other things is the touching or strong bumping of the control element on the sliding guide path, especially on the sidewalls of the sliding guide path.
Now the object of the present invention is to provide an improved drive device in relation to the state of the art. Particularly, the noise development should be reduced.
That object is attained by a drive device with the features discussed below. Thus, according to the invention it is provided that the sliding guide path—outside an optionally present latch recess—has differently hard sidewall regions in certain areas. These differently hard sidewall regions are enabling to implement the sliding guide path in such a way that those sidewall regions are provided with an appropriate different hardness or surface design, where a particularly high noise development is determined in the area of the sliding guide path.
There are indeed publications which show a resilient latch recess, for example the resilient leg of the spring element in the latch recess region of the DE 10 2011 002 212 A1 or the resilient stopping element as a part of the latch recess of the CA 2 743 055 A1. This resilience, however, solely serves to enable an unlocking by pulling into opening direction and not for preventing noise emergence. In contrast, the sliding guide path of the drive device according to the invention comprises—expressed in other words—in certain areas differently hard sidewall regions, wherein, if the sliding guide path comprises a latch recess, these differently hard sidewall are provided outside of this latch recess.
Particularly preferred it can be provided that the sliding guide path has at least one hard sidewall region and at least one soft sidewall region. Thus, the soft sidewall region serves as a stop for the control element in the particularly stressed or noise-prone sections. These sections are especially found where the sliding guide path has a large guiding function for the control element. In the other sections where only a small guiding function is necessary—this means where the control element by itself without guiding moves almost exactly along the sliding guide path—the sidewall region can be formed hard.
The whole sliding guide path can be composed of different parts. It can also be present as a separate component of the drive device. Particularly preferred it can be provided that the sliding guide path is provided in a carrier made of plastic, preferably made of polycaprolactam, wherein the sidewall regions are at least partly made of the material of the carrier itself. Particularly preferred the plastic of the carrier is an injection-molded part. As an alternative to the production out of polycaprolactam this carrier can also consist of comparable thermoplastics or semi-crystalline thermoplastics. Also plastic composites are possible.
For establishing the soft sidewall regions in principle two variants can be used. These variants can also be present mixed in a single sliding guide path. Thus, according to the first variant it can be provided that the of the sidewall region itself is softer and therefore more resilient. This is so to speak a “material-based” variant for establishing a soft sidewall region. There is, however, also the possibility of “geometrically” establishing a softer sidewall region. In this case the material itself does not have to be softer than for example in the hard sidewall regions, but the sidewall is resilient by a thinner formation of the sidewall and therefore the sidewall is “soft” and also formed resilient when impacting on the side element.